1. Field of the Invention
The present invention relates to a mechanism for locking a door of a card slot formed in an electronic device such as a digital camera. The locking mechanism unlocks the door to allow a removable card to be inserted into the card slot only when the removable card is a compatible removable card that is connectable to the electronic device.
2. Description of the Related Art
Various types of removable cards having different shapes and sizes which are inserted into a card slot formed in an electronic device such as a digital camera (for instance, removable memory cards which are utilized as image storing media for digital cameras) are available on the market. Therefore, there is the possibility of an incompatible removable card, having a smaller size than a compatible removable card, being inserted into the card slot by mistake. Once such an incompatible removable card is inserted into the card slot, it is often the case that the card jams in the card slot, and in the worst cases, the card connector provided in the card slot is damaged or foreign object is accidentally inserted into the card slot.
It should be noted that in the present specification the length of an insertion end face of a removable card in the lengthwise direction is referred to as the width of the removable card, and the length of the same insertion end face in the transverse direction is referred to as the thickness of the removable card. The lengthwise direction of the card slot (insertion opening of the card slot) corresponds to the widthwise direction of the removable card.
The primary object of the present invention is to provide a card slot door locking mechanism having simple and low-cost structure which makes it possible to effectively prevent any incompatible removable card or foreign object from entering into the card slot.
To achieve the object mentioned above, according to an aspect of the present invention, a card slot door locking mechanism is provided, including a pair of doors, each of the pair of doors being rotatable between a closed position to close a card slot and an open position to allow a removable card to be inserted into the card slot, and being biased to the closed position; a pair of open guide surfaces, each of the pair of open guide surfaces being formed on each respective door of the pair of doors so that the pair of doors concurrently rotate to the open position when the pair of open guide surfaces are concurrently pushed by the removable card, the pair of open guide surfaces being apart from each other in a lengthwise direction of the card slot; and a pair of barrier surfaces, each of the pair of barrier surfaces being formed on each respective door of the pair of doors, positioned between the pair of open guide surfaces in the lengthwise direction of the card slot, so that at least one of the pair doors is prevented from rotating toward the open position when at least one of the pair of barrier surfaces is pushed by an object other than the removable card without pushing the pair of open guide surfaces concurrently.
Preferably, each of the pair of open guide surfaces is inclined with respect to a card insertion direction so that a point on the each of the pair of open guide surfaces moves substantially toward the closing direction of each respective the pair of doors as the point moves along the card insertion direction.
Preferably each of the pair of barrier surfaces is inclined with respect to a card insertion direction so that a point on the each of the pair of barrier surfaces moves substantially toward the opening direction of each respective the pair of doors as the point moves along the card insertion direction.
In an embodiment, the card slot door locking mechanism further includes at least one stopper which determines the closed position of each of the pair of doors.
The card slot can be incorporated in a digital camera, and the removable card can be a removable memory card in which image data is recorded.
According to another aspect of the present invention, a card slot door locking mechanism is provided, including a first door and a second door, each of the first and second doors being rotatable between a closed position to close a card slot and an open position to allow a removable card to be inserted into the card slot, and being biased to the closed position; a first open guide surface formed on the first door and a second open guide surface formed on the second door, the first and second open guide surfaces being apart from each other in a lengthwise direction of the card slot; and a first barrier surface formed on the first door and a second barrier surface formed on the second door, the first and second barrier surfaces being positioned between the first open guide surface and the second open guide surface in the lengthwise direction of the card slot. The first door and the second door concurrently rotate to the open position when the first and second open guide surfaces are concurrently pushed toward a card insertion direction by the removable card. At least one of the first and second doors is prevented from rotating toward the open position when at least one of the first and second barrier surfaces is pushed toward the card insertion direction by an object other than the removable card without pushing the first and second open guide surfaces concurrently.
Preferably, the first open guide surface is positioned closer to an insertion opening of the card slot than the first barrier surface, and the second open guide surface is positioned closer to the insertion opening of the card slot than the second barrier surface.
In an embodiment, each of the first door and the second door includes two parallel arms, each of which is pivoted at one end thereof and extends substantially toward the card insertion direction from the one end which is pivoted; and a barrier arm which extends between the two parallel arms in the lengthwise direction of the card slot to connect the other ends which are not pivoted of the two parallel arms together. The first open guide surface is formed on one of the two parallel arms of the first door, and the second open guide surface is formed on one of the two parallel arms of the second door. The first barrier surface is formed on the barrier arm of the first door, and the second barrier surface is formed on the barrier arm of the second door.
In an embodiment, the two parallel arms of the first door and the two parallel arms of the second door are pivoted about a common shaft which extends substantially parallel to the lengthwise direction of the card slot.
In an embodiment, the first open guide surface and the second open guide surface substantially lie at the same position with respect to the card insertion direction, and the first barrier surface and the second barrier surface substantially lie at the same position with respect to the card insertion direction.
In an embodiment, the first barrier surface includes a plurality of first barrier surfaces, the second barrier surface includes a plurality of second barrier surfaces, and the plurality of first barrier surfaces and the plurality of second barrier surfaces are arranged along the lengthwise direction of the card slot in an alternate configuration.
In an embodiment, the first barrier surface is positioned adjacent to the second open guide surface in the lengthwise direction of the card slot, and the second barrier surface is positioned adjacent to the first open guide surface in the lengthwise direction of the card slot.
According to another aspect of the present invention, a card slot door locking mechanism is provided, including a first door which is rotatable between a first-door-closed position, in which the first door closes a card slot, and a first-door-open position, in which the first door opens the card slot to allow a removable card to be inserted into the card slot, the first door being biased to rotate in a direction towards the first-door-closed position; a second door which is rotatable between a second-door-closed position, in which the second door closes the card slot, and a second-door-open position, in which the second door opens the card slot to allow the removable card to be inserted into the card slot, the second door being biased to rotate in a direction towards the second-door-closed position; a first open guide surface which is formed on the first door so that the first door rotates toward the open position thereof when a pushing force is applied against the first open guide surface in a card insertion direction; a second open guide surface which is formed on the second door so that the second door rotates toward the open position thereof when a pushing force is applied against the second open guide surface in the card insertion direction; a first barrier surface which is formed on the first door so as to prevent the first door from rotating toward the open position thereof when a pushing force is applied against the first barrier surface in the card insertion direction without applying a pushing force on the first open guide surface; and a second barrier surface which is formed on the second door so as to prevent the second door from rotating toward the open position thereof when a pushing force is applied against the second barrier surface in the card insertion direction without applying a pushing force on the second open guide surface. The first open guide surface and the second open guide surface are arranged apart from each other in a lengthwise direction of the card slot. The first barrier surface and the second barrier surface are positioned between the first open guide surface and the second open guide surface in the lengthwise direction of the card slot.
The present disclosure relates to subject matter contained in Japanese Patent Application No.2000-010811 (filed on Jan. 19, 2000) which is expressly incorporated herein by reference in its entirety.